1. Field of Invention
This invention generally relates to the field of automatically processing image data.
2. Description of Related Art
In automatically processing image data, it is often desired to determine the average background and the foreground levels that appear in the image data. These levels can be used to suppress background noise and to enhance the contrast between the foreground and background portion of the image data. One conventional method for determining the average background and foreground levels is to inspect a histogram determined from the image data. Typically, this histogram is bimodal, with a peak near the foreground image value and a peak near the background image value. The locations of the two peaks determine the background and foreground levels.
A significant drawback associated with this conventional method is that generally the histogram is costly in one or both of computation and memory resources. A second significant drawback associated with this conventional method is that a histogram over a small region of an image is too noisy to allow the locations of the peaks to be determined.